Additional Emission Research Articles

Little Red Dots: Rapidly Growing Black Holes Reddened by Extended Dusty Flows

Abstract The James Webb Space Telescope (JWST) observations have revolutionized extragalactic research, particularly with the discovery of little red dots (LRDs), which have been discovered as a population of dust-reddened broad-line active galactic nuclei (AGNs). Their unique V-shaped spectral feature, characterized by a red optical continuum and a UV excess in the rest frame, challenges us to discern the relative contributions of the galaxy and AGN. We study a spectral energy distribution (SED) model for LRDs from rest-frame UV to infrared bands. We hypothesize that the incident radiation from an AGN, characterized by a typical SED, is embedded in an extended dusty medium with an extinction law similar to those seen in dense regions such as Orion Nebula or certain AGN environments. The UV−optical spectrum is described by dust-attenuated AGN emission, featuring a red optical continuum at λ > 4000 Å and a flat UV spectral shape established through a gray extinction curve at λ < 3000 Å, due to the absence of small-size grains. There is no need for additional stellar emission or AGN scattered light. In the infrared, the SED is shaped by an extended dust and gas distribution (γ < 1; ρ ∝ r −γ ) with characteristic gas densities of ≃10–103 cm−3, which allows relatively cool dust temperatures to dominate the radiation. As a result, these dust structures shift the emission energy peak from near-infrared to mid-infrared bands in the rest frame; for sources at z ~ 4–7, the corresponding wavelengths shift from the JWST/MIRI to Herschel range. This model, unlike the typical AGN hot torus models, can produce an infrared SED flattening that is consistent with LRD observations through JWST MIRI. Such a density structure can arise from the coexistence of inflows and outflows during the early assembly of galactic nuclei. This might be the reason why LRDs emerge preferentially in the high-redshift Universe younger than 1 billion years.

First-Principles Understanding of Mono- and Dual-Emissions in AZnOS:Bi3+ (A = Ba, Ca) Phosphors

The AZnOS:Bi3+ (A = Ba, Ca) phosphors exhibit mono- and dual-emission phenomena based on the different choices of cation, making them an ideal prototype for dual-emission mechanism studies of Bi3+ ions. Here, first-principles calculations were performed to investigate the site occupancy, defect levels, and luminescence properties of the AZnOS:Bi3+ systems. The formation energy calculations show that the bismuth dopants are mainly in the trivalent charge state, with the Bi3+ ions preferring the Ca sites in CaZnOS but the Zn sites in BaZnOS. Such cation-selective occupancy mainly results in the difference between the mono- and dual-emission phenomena in the two hosts. The excitation and emission energies predicted by calculations are in good agreement with the measurements. Our calculations show that the lowest excited state 3P0,1 provides the dominant emission in both CaZnOS:Bi3+ and BaZnOS:Bi3+ phosphors. In light of the experimental and theoretical results, the metastable excited state of Bi2+ + hVBM (hole at the valence band maximum) is the origin of the additional emission bands in BaZnOS:Bi3+. These results provide the basis of emission band tuning and novel material design for Bi3+-doped phosphors.

Observations of UX Ori in deep minima with the Nordic Optical Telescope. I. Analysis of spectral lines

UX Orionis stars are the most active young stars; they undergo sporadic fadings of 2 to 4 magnitudes in the V-band, due to variable circumstellar extinction caused by a nearly edge-on star--disc system. The long-lasting monitoring of a number of stars of this type with the Nordic Optical Telescope from 2019 to 2024 has given a rich collection of material of high-resolution (R ∼ 25000) spectra obtained during different brightness states of the stars. In this paper we present the results of observations for UX Ori itself. Until now only one spectrum of high resolution had been obtained for this star during brightness minimum, making it difficult to do a comprehensive analysis. Our aim is to analyse how different spectral lines change during such irregular fading events, when the star is going in and out of eclipses, obscured by dust along the line of sight. For this purpose we provide a comparative analysis of the profiles and equivalent widths of the spectral lines belonging to the different atoms and ions. In addition we compare the results for UX Ori with those made for another target in our sample: RR Tau. Common features of variability are revealed: (1) a strengthening of the Hα line relatively to the continuum during eclipses; (2) the appearance of additional emission on the frequencies of photospheric lines (e.g. FeII, CaII, SiII). The different behaviour of the spectral lines during fading found for UX Ori and RR Tau may be caused by two effects: a different contribution of the scattered light to the stellar flux during eclipses or a less intense disc wind of UX Ori.

Temperature-dependent color-tunable persistent luminescence in Ba0.95Sr0.05Ga2-yGdyO4:Bi3+ phosphor for advanced anti-counterfeiting.

As emerging anti-counterfeiting materials, persistent luminescence (PersL) materials have attracted much attention owing to their particular luminescent properties, including durable luminescence, facile identification, high security and environment-friendly. Especially, exploiting color-tunable dynamic afterglow materials that facilitate the use of advanced technology such as multi-mode dynamic anti-counterfeiting remains of great realistic significance. Herein, a series of Ba0.95Sr0.05Ga2-yGdyO4:Bi3+ phosphors with tunable photoluminescence and PersL were synthesized by the cationic substitution strategy. The displacement of Ga3+ by Gd3+ induces an additional blue emission owing to the generation of a new Bi3+ luminescence center. The pure white light is realized in Ba0.942Sr0.05Ga1.9Gd0.1O4:0.8%Bi3+,0.25%K+ when excited by 325nm light. Besides, color-tunable emission is triggered by changing the excitation wavelength or temperature. Significantly, excellent room-temperature PersL and dramatically intensified PersL with tunable color output under thermal stimulation are clearly discernible. Such properties result from the existence of multiple Bi3+ luminescent centers and traps. These findings open up new ideas to produce color-tunable dynamic PersL materials for advanced anti-counterfeiting, information storage and encryption.

Carbon Tax Refund System for Recycling in Reverse Supply Chain Network to Minimize GHG Emissions and Costs

Material recycling is vital for achieving carbon neutrality because using recycled materials helps avoid greenhouse gas (GHG) emissions that result from using virgin material. Carbon tax has been introduced in many countries to reduce GHG emissions. As recycling can prevent additional GHG emissions, the carbon tax should be refunded based on the GHG volume saved by recycling. The incentive of carbon tax refund can help promote recycling as an environment-friendly and economical activity. To retrieve material values from end-of-life (EOL) products, a reverse supply chain network should be designed based on the status and value of EOL products. This study introduces carbon tax refund into the reverse supply chain network for maximizing saved GHG emissions and minimizing cost. The bi-objective model is formulated using ϵ constraint method and integer programming. Numerical experiments were conducted based on the recycling of a vacuum cleaner and a laptop. The monetary rate at which the carbon tax refund became economically attractive differed according to product type. Thus, variable carbon tax refund rates would be needed, based on product type, to incentivize recycling.

The Impact of Quarrying Activities on Air Quality and Public Health: A Case Study in Warwickshire

Poor air quality is well-documented for its links to health issues such as asthma, cancer, and autoimmune diseases, posing particularly high risks to children and vulnerable populations. This study utilizes a mixed-methods approach to evaluate the air pollution levels that school students and local residents are currently exposed to, along with the potential impact of a proposed 220-acre sand and gravel quarry, which would increase heavy goods vehicle (HGV) traffic near the community. Monitoring was conducted in multiple locations, including the village High Street, a 250-student primary school, a private residence opposite the school, and 350 meters from an active quarry site. Results indicate that levels of particulate matter (PM<sub>10</sub> and PM<sub>2.5</sub>) frequently exceeded both national and WHO safety thresholds, particularly during peak traffic hours, which exacerbated the decline in air quality. If the new quarry is approved, air pollution levels are expected to further increase due to intensified HGV traffic and additional emissions from quarry activities, raising serious concerns about potential health impacts on local residents. For over twenty years, planning officers, regulatory bodies, and developers have relied predominantly on desktop modelling to assess the health risks associated with quarry activities, often using outdated and limited data that fail to capture the current conditions and real-world risks. Authorities maintain that there is "no evidence" of health risks for residents near quarries, a claim based on the absence of direct scientific studies rather than conclusive safety. This research underscores the urgent need for robust, ground-level data to inform decision-making and safeguard public health, particularly given the increased exposure risks to children attending school within the impact zone. The study’s findings strongly suggest that new quarrying activities could significantly compromise local air quality and increase health risks, highlighting the inadequacies of current regulatory assessments.

Urban Management for Building-Sector Decarbonization: Focusing on the Role of Low-Carbon Policies

The building sector is a major source of anthropogenic carbon emissions worldwide. While existing studies have extensively explored the socioeconomic and technological impacts on carbon emissions generated from building operations, few have assessed the effectiveness of low-carbon policies in curbing the increasing trend of building sector carbon emissions. This study examines the impacts of low-carbon policy intensity on building sector carbon emissions using a two-way fixed effects model on a 6-year panel (2015–2020) dataset for 286 cities in China. Our findings indicate that, on average, the aggregated intensity of low-carbon policies fails to pose any significant impacts on carbon emissions from building operations. This is partly due to the variations in different types of policy. Specifically, a 10% increase in the intensity of energy conservation policy results in a 0.05% decrease in carbon emissions, whereas capacity utilization policies are associated with an increase in building-operation carbon emissions. Moreover, these policy–emission relationships vary across building types and end-use sources. In particular, energy conservation policies are negatively associated with emissions from cooking and heating, but positively related to emissions generated from appliances and cooling. In comparison, capacity utilization policies tend to encourage additional emissions from most sources. This study highlights the partial effectiveness of energy conservation policies in curbing building sector carbon emissions and underscores the need for additional efforts in tackling the rebound effects to realize building sector decarbonization.

Revisiting the BE99 method for the study of outflowing gas in protostellar jets

An established method for measuring the hydrogen ionisation fraction in shock-excited gas is the BE99 method, which utilises six bright forbidden emission lines: S\,II N\,II 6583, and O\,I 6363. The main assumptions of this technique are that the gas is in a low-excitation state ($x_ e < 0.3$) and that the equilibrium of the underlying ionisation network is reached. Our aim is to extend the BE99 method by including more emission lines in the blue and near-infrared part of the spectrum ($ and by considering higher hydrogen ionisation fractions ($x_ e > 0.3$). In addition, we investigate how a non-equilibrium state of the gas and the presence of extinction influence the BE99 technique. We numerically solved a network of ionisation reactions in the time domain, which lead to the BE99 equilibrium. We applied the BE99 method on synthetic spectra also in the non-equilibrium state. We extented the BE99 technique to higher ionisation fractions by considering additional reactions, which involve higher ionisation states of oxygen, nitrogen, and sulphur. We tested our concepts on the low-excitation outflow of Par Lup 3-4 and the high-excitation 244-440 Proplyd in Orion. Many additional emission line ratios can in principle be exploited as extended curves (or stripes) in the ($x_ e T_ e $) diagram. If the BE99 equilibrium is reached and extinction is corrected for, all stripes overlap in one location in the ($x_ e T_ e $) diagram indicating the existing gas parameters. We find that the BE99 equilibrium is reached faster than the hydrogen recombination time. The application to the Par Lup 3-4 outflow shows that the classical BE99 lines together with the N\,I lines do not meet in one location in the ($x_ e T_ e $) diagram. This indicates that the gas parameters derived from the classical BE99 method are not fully consistent with other observed line ratios. A multi-line approach is necessary to determine the gas parameters. From our analysis we derive $n_e cm cm $, $T_e = 7\,600\ K K $, and $x_e 0.027-0.036$ for the Par Lup 3-4 outflow. For the 244-440 Proplyd we were able to use the line ratios of S\,II O\,I and OII 7330 in the BE99 diagram to estimate the ionisation fraction at knot E3 ($x_e = 0.58 The BE99 method can be extended by utilising more emission line ratios in the ($x_ e T_ e $) diagram and considering higher ionisation states. Exploiting new line ratios reveals more insights on the state of the gas. Our analysis indicates, however, that a multi-line approach is more robust in deriving gas parameters, especially for high-density gas.

Modelling long-term greenhouse gas mitigation pathways for Mongolia

Abstract Mongolia’s faces substantial challenges to reduce its Greenhouse Gas (GHG) emissions due to a reliance on coal to meet electricity, heat and other energy demand and large livestock emissions. Despite this, Mongolia has committed to reduce GHG emissions by 22.7% in 2030 compared to a baseline emission scenario. Greenhouse gas mitigation assessments for Mongolia have focussed on actions to achieve emission reductions by 2030, but not on the potential for further reduction over the longer-term. This study addresses this gap through the development of long-term (2050) GHG emission pathways for Mongolia. From a technical mitigation potential perspective, these pathways aim to inform what level of GHG reduction targets Mongolia could commit to for the period after its current target expires. Greenhouse gas emissions are quantified for historic years (2010-2019) for all major GHG emitting source sectors, and projected to 2050 based on the population and socioeconomic development outlined in Mongolia’s Sustainable Development Vision 2050. Finally, mitigation scenarios that model implementation of 49 specific mitigation measures are developed, to quantify their emission reduction potential. Without mitigation, GHG emissions were estimated to increase by 67% and 139% in 2030 and 2050, respectively, compared to 2019 levels (39 million tonnes CO2-eq emissions). Implementation of the 49 mitigation measures could reduce GHG emissions by 40% in 2050 compared to the baseline. This study highlights that post-2030, Mongolia could increase its climate change mitigation ambition. Renewable Electricity generation, and energy efficiency were the measures that could achieve the majority of these additional emission reductions. However, despite the achieve emission reductions in excess of those within current commitments, there remains a substantial gap between the emission reduction potential of technically feasible measures currently being considered in Mongolia’s climate change mitigation planning, and full decarbonisation.

Assessing the impact of strictly protecting 30%–50% of global land on carbon dynamics in natural and agricultural ecosystems

Societal Impact StatementStrictly protected areas for nature conservation are a key policy to benefit biodiversity and climate change mitigation since reduced deforestation and ecosystem restoration enhance carbon stocks. However, there is controversy regarding their potential societal impacts, such as competition for land and food security. Here, we investigate the implications of protecting 30% and 50% of the global ice‐free land surface on the spatiotemporal dynamics of ecosystem carbon uptake and losses, agricultural land use and synergies with food production. The study provides insights into the role of protected areas on the global terrestrial carbon store, contributing to climate change mitigation and biodiversity conservation efforts.Summary Agriculture and forestry use around half of the global ice‐free land and are major drivers of biodiversity loss. For this reason, the post‐2020 Global Biodiversity Framework of the Convention on Biological Diversity (CBD) targets at least 30% of protected global land by 2030. This study evaluates the impacts of different land‐use change scenarios on the storage of carbon in terrestrial ecosystems and trade‐offs and synergies in the global food production system by comparing a reference scenario with no additional protected area expansion targets and two scenarios with strict area‐based protection targets of 30% and 50% of the ice‐free land surface. A net global gain in carbon storage up to 110 PgC was projected for 2056–2060 in the protection scenarios compared to the reference scenario (equivalent to around 10 years of current global anthropogenic C emissions). However, regional disparities in carbon storage are large and include carbon losses in areas identified as having—at least on a decadal perspective—‘irrecoverable’ carbon. In the protection scenarios, cropland expansion in some regions is accompanied by intensification of production with an increase of up to 8% in the use of N fertiliser, which may lead to pollution and additional greenhouse gas emissions.

Procreative Prerogatives and Climate Change

ABSTRACTOne of the most provocative claims in current climate ethics is that we ought to have fewer children, because procreation brings new people into existence and thereby causes large amounts of additional greenhouse gas emissions. The public debate about procreation and climate change is frequently framed in terms of the question of whether people may still have any children at all. Yet in the academic debate it is a common position that, despite the large carbon impact of procreation, it is still permissible to have one or two children per couple, if having children is needed for the parents' lives to go well. In this article, we propose a defence and a principled formulation of this procreative prerogative: agents are permitted to procreate if the goods that procreation provides are essential to their lives going well and cannot be replaced by other goods, nor be realized by lower‐emissions alternatives. This principle implies that procreative decisions require case‐by‐case assessment in which agents' self‐reflection, individual circumstances, and social context play a significant role.

Comparative life cycle assessments of laboratory and Pilot-scale Mechanochemical processes for producing carbonated mineral products as cement substitutes

The use of carbonated mineral products in cement production reduces carbon emissions and enhances durability. This study evaluated the environmental sustainability of using mineral carbonated biomass fly ash (BFA) as a partial cement replacement in European cement production. Laboratory-scale and simulated large-scale scenarios were analysed. Incorporating 20% mineral carbonated BFA showed potential for a 33% reduction in the annual Global Warming Potential (GWP) of cement products. Energy consumption factors, such as ball milling and mineral carbonation processes, were evaluated using a machine learning model and comminution flow sheet model simulations. The machine learning model predicted CO2 absorption and energy requirements for mineral carbonation, showing greater efficiency in large-scale scenarios. Life cycle assessments consistently revealed GWP reductions for OPC-BFA mixtures, with additional emissions reductions when incorporating flow sheet modelling and machine learning data. However, the study's limitations include simplified CO2 flue gas treatment, use of the mean EU electricity mix, exclusion of transportation impacts, and reliance on simulation data. Additionally, the cement mix exhibited reduced compressive strength. This study highlights the potential of mineral carbonated BFA to reduce cement production's environmental impact while emphasising the need for balanced optimisation between sustainability and material performance.

Visible‐Light‐Driven Solid‐State Fluorescent Photoswitches for High‐Level Information Encryption

AbstractDeveloping visible‐light‐driven fluorescent photoswitches in the solid state remains an enormous challenge in smart materials. Such photoswitches are obtained from salicylaldimines through excited‐state intramolecular proton transfer (ESIPT) and subsequent cis‐trans isomerization strategies. By incorporating a bulky naphthalimide fluorophore into a Schiff base, three photoswitches achieve dual‐mode changes (both in color and fluorescence) in the solid state. In particular, the optimal one generates triple fluorescence changing from green, to yellow and finally to orange upon visible‐light irradiation. This switching process is fully reversible and can be repeated at least 10 times without obvious attenuation, suggesting its good photo‐fatigue resistance. Mechanism studies reveal that the naphthalimide group not only enables the tuning of multicolor with an additional emission, but also induces a folded structure, reducing molecular stacking and facilitating ESIPT and cis‐trans isomerization. As such, photopatterning, ternary encoding and transient information recording and erasing are successfully developed. The present study provides a reliable strategy for visible‐light‐driven fluorescent photoswitches, showing implications for advanced information encryption materials.

Recommendations on Imaging in the Context of Alzheimer's Disease-Modifying Therapies from the CCNA Imaging Workgroup.

Disease-modifying therapies (DMTs) for Alzheimer's disease (AD) are emerging following successful clinical trials of therapies targeting amyloid beta (Aβ) protofibrils or plaques. Determining patient eligibility and monitoring treatment efficacy and adverse events, such as Aβ-related imaging abnormalities, necessitates imaging with MRI and PET. The Canadian Consortium on Neurodegeneration in Aging (CCNA) Imaging Workgroup aimed to synthesize evidence and provide recommendations on implementing imaging protocols for AD DMTs in Canada. The workgroup employed a Delphi process to develop these recommendations. Experts from radiology, neurology, biomedical engineering, nuclear medicine, MRI and medical physics were recruited. Surveys and meetings were conducted to achieve consensus on key issues, including protocol standardization, scanner strength, monitoring protocols based on risk profiles and optimal protocol lengths. Draft recommendations were refined through multiple iterations and expert discussions. The recommendations emphasize standardized acquisition imaging protocols across manufacturers and scanner strengths to ensure consistency and reliability of clinical treatment decisions, tailored monitoring protocols based on DMTs' safety and efficacy profiles, consistent monitoring regardless of perceived treatment efficacy and MRI screening on 1.5T or 3T scanners with adapted protocols. An optimal protocol length of 20-30 minutes was deemed feasible; specific sequences are suggested. The guidelines aim to enhance imaging data quality and consistency, facilitating better clinical decision-making and improving patient outcomes. Further research is needed to refine these protocols and address evolving challenges with new DMTs. It is recognized that administrative, financial and logistical capacity to deliver additional MRI and positron emission tomography scans require careful planning.

Degradation Analysis of Exciplex-Based Organic Light-Emitting Devices Using Carbazole-Based Materials.

A spectral shift and new emission bands in the green and red regions have been observed in deep blue exciplex-based organic light-emitting diodes (OLEDs) using carbazole-based materials, namely, tris(4-carbazoyl-9-ylphenyl)amine (TCTA). To deeply understand the origin of these new bands, single-layer and bilayer TCTA-based OLEDs subjected to electrical and optical (ultraviolet (UV)) stresses were investigated by using various optical, electrical, morphological, and chemical measurements. The results showed that the stress-induced emission bands primarily originate from morphological changes rather than chemical changes. The accumulation of excitons in the TCTA layer induces molecular aggregation, leading to the formation of electrically active electronic states, namely, electroplexes and electromers, which lead to the appearance of additional emission bands in green and red regions. Impedance spectroscopy measurements on single-layer OLEDs complemented this study. The results showed that TCTA degradation affects charge injection and transport. It was concluded that the stress-induced emission bands are caused by aggregate domain formation and are closely linked to the formation of electrically active defects, which act as trap states for charge carriers in the TCTA band gap.

Managing the Global Wetland Methane-Climate Feedback: A Review of Potential Options.

Methane emissions by global wetlands are anticipated to increase due to climate warming. The increase in methane represents a sizable emissions source (32-68 Tg CH4 year-1 greater in 2099 than 2010, for RCP2.6-4.5) that threatens long-term climate stability and poses a significant positive feedback that magnifies climate warming. However, management of this feedback, which is ultimately driven by human-caused warming and thus "indirectly" anthropogenic, has been largely unexplored. Here, we review the known range of options for direct management of rising wetland methane emissions, outline contexts for their application, and explore a global scale thought experiment to gauge their potential impact. Among potential management options for methane emissions from wetlands, substrate amendments, particularly sulfate, are the most well studied, although the majority have only been tested in laboratory settings and without considering potential environmental externalities. Using published models, we find that the bulk (64%-80%) of additional wetland methane will arise from hotspots making up only about 8% of global wetland extent, primarily occurring in the tropics and subtropics. If applied to these hotspots, sulfate might suppress 10%-21% of the total additional wetland methane emissions, but this treatment comes with considerable negative consequences for the environment. This thought experiment leverages results from experimental simulations of sulfate from acid rain, as there is essentially no research on the use of sulfate for intentional suppression of additional wetland methane emissions. Given the magnitude of the potential climate forcing feedback of methane from wetlands, it is critical to explore management options and their impacts to ensure that decisions made to directly manage-or not manage-this process be made with the best available science.

Effects of industrial hydrogen-rich gases on the performance of the spark ignition engine under various combustion modes

Hydrogen is emerging as a promising alternative to traditional fossil fuels for the transportation. Additionally, the hydrogen-rich gases (HRG) can produce on a large scale during the process of chemical production. In this study, the influences of HRG on the performance behaviors of the spark ignition (SI) engine are comprehensively analyzed under various combustion modes and operating conditions. The experimental results indicate that with increasing the lambda, the torque of the test engine can maintain the target value under equivalent ratio and lean combustion modes, while it sharply decreases under ultra-lean combustion. When the value of the lambda is 1.5, the brake thermal efficiency (BTE) and brake specific hydrogen consumption (BSHC) of the HRG SI engine respectively reach up to 33.6% and 89.1 g/kW.h, yielding superior fuel economy. The NOx emissions of the HRG SI engine firstly increase and then decrease with increasing lambda, reaching the peak value at the lambda of 1.1. In addition, the NOx, CO, and HC emissions of the HRG SI engine greatly reduce when the lambda is approximately 1.5. Consequently, using HRG partially substitute the traditional fossil gasoline in the SI engine can benefit to achieve energy conservation and emissions reduction in transportation section.

Modeling of Long-term Afterglow Counterparts to Gravitational Wave Events: The Full View of GRB 170817A

The arrival of gravitational wave astronomy and a growing number of time-domain-focused observatories are set to lead to an increasing number of detections of short gamma-ray bursts (GRBs) launched with a moderate inclination to Earth. Being nearby events, these are also prime candidates for very long-term follow-up campaigns and very long-baseline interferometry, which has implications for multi-messenger modeling, data analysis, and statistical inference methods applied to these sources. Here, we present a comprehensive modeling update that directly incorporates into afterglowpy astrometric observations of the GRB position, Poissonian statistics for faint sources, and modeling of a trans-relativistic population of electrons. We use the revolutionary event GW170817 to demonstrate the impact of these extensions both for the best-fit physics parameters and model selection methods that assess the statistical significance of additional late-time emission components. By including in our analysis the latest Chandra X-ray observations of GRB 170817A, we find only weak evidence (≲2σ) for a new emission component at late times, which makes for a slightly more natural fit to the centroid evolution and prediction for the external medium density.

Carbon emission reduction associated with dapagliflozin compared to standard of care in the UK: translating the DAPA-HF and DELIVER trial findings to an environmental context

Abstract Background Healthcare systems account for 4–5% of UK national greenhouse gas emissions with delivery of care a major component.1 Preventing events that use healthcare resources should contribute to a reduction in emissions, in addition to the primary humanitarian aim of improving patient outcomes. The Dapagliflozin And Prevention of Adverse-outcomes in Heart Failure (DAPA-HF) and the Dapagliflozin Evaluation to Improve the Lives of Patient with Preserved Ejection Fraction Heart Failure (DELIVER) trials demonstrated that dapagliflozin reduced the frequency of hospitalizations for heart failure (hHF), urgent heart failure visits (UHFV) and cardiovascular (CV) death for patients with heart failure (HF).2,3 Purpose The study objective was to translate predicted differences in clinical events associated with dapagliflozin use in HF to a predicted carbon emission reduction from a UK perspective. Methods A previously published model4 based on pooled DAPA-HF and DELIVER event rates was used to predict hHF, UHFV and CV deaths in a cohort of 1,000 HF patients over a 3-year time horizon. Composite greenhouse gas (GHG) emissions (as kg CO2 equivalent) were calculated from components sourced from the Sustainable Healthcare Coalition’s Care Pathway Calculator according to assumed clinical pathways and were applied to predicted incidence of hHF, UHFV and CV death events. Average length of stay was sourced from the National Heart Failure Audit.5 CV deaths occurring outside hospital were assumed to incur no additional carbon emission except that associated with cremation. Proportion of funerals by cremation and associated GHG emissions were sourced from literature.6,7 Future emissions were not discounted, representing the NHS’s aim to approach ‘net zero’. Results Over a 3-year time horizon, treatment with dapagliflozin was projected to prevent 74 hHF events, 9 UHFV events and 20 CV deaths per 1,000 patients treated versus placebo. Total estimated GHG emissions associated with hHF (233.2 kg CO2e), UHFV (177.4 kg CO2e), and CV death (251.4 kg CO2e) were 85,660 kg CO2e per 1,000 patients treated with dapagliflozin versus 109,618 kg CO2e per 1,000 patients treated with placebo. The projected total reduction associated with dapagliflozin treatment was 23,958 kg CO2e over 3 years, a 22% reduction versus placebo. Per population (~690,000 HF patients), total emissions prevented by dapagliflozin over 3 years were projected to be equivalent to driving 42 million miles in an average gasoline-powered passenger vehicle. Conclusion While the main aim of any therapeutic intervention is to save lives and improve patient outcomes, to capture the full spectrum of benefit to stakeholders the environmental consequences of new therapies should be considered in addition to their clinical and economic effects. Our analysis suggests treating patients with dapagliflozin may contribute to reducing the environmental burden of HF in addition to improving patient outcomes.

Life-cycle cost assessment of hull protection technologies considering their effect on the environmental friendliness of fishing vessels

Biofouling represents a global challenge for the maritime industry, affecting vessel performance and environmental footprint. This paper analyses various antifouling technologies to reduce the vessel's environmental impact and its operating costs by reduced fuel consumption and less frequent dry-docking. It evaluates both passive and active technologies – passive referring to antifouling coatings and active involving systems that continuously prevent biofouling using energy. The methodology employs mathematical models to quantify the additional resistance and emissions caused by biofouling. Using the case of a fishing vessel operating in the Adriatic Sea, operational features and potential economic and environmental benefits resulting implementing an innovative biofouling protection system are analysed. Economic analysis includes a comprehensive cost structure, investment details, maintenance and operating costs, and possible future carbon taxation scenarios. The research indicates that active antifouling protection is more efficient than passive protection, including a potential reduction of the required power of up to 120 kW, leading to decreased fuel consumption and lower environmental impact, particularly at higher speeds. Despite higher initial investments, life-cycle cost analysis favours active protection systems.